src/bin/lttng-sessiond/cmd.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <assert.h>
  20 #include <urcu/list.h>
  21 #include <urcu/uatomic.h>
  22
  23 #include <common/defaults.h>
  24 #include <common/common.h>
  25 #include <common/sessiond-comm/sessiond-comm.h>
  26 #include <common/relayd/relayd.h>
  27
  28 #include "channel.h"
  29 #include "consumer.h"
  30 #include "event.h"
  31 #include "kernel.h"
  32 #include "kernel-consumer.h"
  33 #include "lttng-sessiond.h"
  34 #include "utils.h"
  35
  36 #include "cmd.h"
  37
  38 /*
  39  * Used to keep a unique index for each relayd socket created where this value
  40  * is associated with streams on the consumer so it can match the right relayd
  41  * to send to.
  42  *
  43  * This value should be incremented atomically for safety purposes and future
  44  * possible concurrent access.
  45  */
  46 static unsigned int relayd_net_seq_idx;
  47
  48 /*
  49  * Create a session path used by list_lttng_sessions for the case that the
  50  * session consumer is on the network.
  51  */
  52 static int build_network_session_path(char *dst, size_t size,
  53                 struct ltt_session *session)
  54 {
  55         int ret, kdata_port, udata_port;
  56         struct lttng_uri *kuri = NULL, *uuri = NULL, *uri = NULL;
  57         char tmp_uurl[PATH_MAX], tmp_urls[PATH_MAX];
  58
  59         assert(session);
  60         assert(dst);
  61
  62         memset(tmp_urls, 0, sizeof(tmp_urls));
  63         memset(tmp_uurl, 0, sizeof(tmp_uurl));
  64
  65         kdata_port = udata_port = DEFAULT_NETWORK_DATA_PORT;
  66
  67         if (session->kernel_session && session->kernel_session->consumer) {
  68                 kuri = &session->kernel_session->consumer->dst.net.control;
  69                 kdata_port = session->kernel_session->consumer->dst.net.data.port;
  70         }
  71
  72         if (session->ust_session && session->ust_session->consumer) {
  73                 uuri = &session->ust_session->consumer->dst.net.control;
  74                 udata_port = session->ust_session->consumer->dst.net.data.port;
  75         }
  76
  77         if (uuri == NULL && kuri == NULL) {
  78                 uri = &session->consumer->dst.net.control;
  79                 kdata_port = session->consumer->dst.net.data.port;
  80         } else if (kuri && uuri) {
  81                 ret = uri_compare(kuri, uuri);
  82                 if (ret) {
  83                         /* Not Equal */
  84                         uri = kuri;
  85                         /* Build uuri URL string */
  86                         ret = uri_to_str_url(uuri, tmp_uurl, sizeof(tmp_uurl));
  87                         if (ret < 0) {
  88                                 goto error;
  89                         }
  90                 } else {
  91                         uri = kuri;
  92                 }
  93         } else if (kuri && uuri == NULL) {
  94                 uri = kuri;
  95         } else if (uuri && kuri == NULL) {
  96                 uri = uuri;
  97         }
  98
  99         ret = uri_to_str_url(uri, tmp_urls, sizeof(tmp_urls));
 100         if (ret < 0) {
 101                 goto error;
 102         }
 103
 104         if (strlen(tmp_uurl) > 0) {
 105                 ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
 106                                 tmp_urls, kdata_port, tmp_uurl, udata_port);
 107         } else {
 108                 ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, kdata_port);
 109         }
 110
 111 error:
 112         return ret;
 113 }
 114
 115 /*
 116  * Fill lttng_channel array of all channels.
 117  */
 118 static void list_lttng_channels(int domain, struct ltt_session *session,
 119                 struct lttng_channel *channels)
 120 {
 121         int i = 0;
 122         struct ltt_kernel_channel *kchan;
 123
 124         DBG("Listing channels for session %s", session->name);
 125
 126         switch (domain) {
 127         case LTTNG_DOMAIN_KERNEL:
 128                 /* Kernel channels */
 129                 if (session->kernel_session != NULL) {
 130                         cds_list_for_each_entry(kchan,
 131                                         &session->kernel_session->channel_list.head, list) {
 132                                 /* Copy lttng_channel struct to array */
 133                                 memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
 134                                 channels[i].enabled = kchan->enabled;
 135                                 i++;
 136                         }
 137                 }
 138                 break;
 139         case LTTNG_DOMAIN_UST:
 140         {
 141                 struct lttng_ht_iter iter;
 142                 struct ltt_ust_channel *uchan;
 143
 144                 cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
 145                                 &iter.iter, uchan, node.node) {
 146                         strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
 147                         channels[i].attr.overwrite = uchan->attr.overwrite;
 148                         channels[i].attr.subbuf_size = uchan->attr.subbuf_size;
 149                         channels[i].attr.num_subbuf = uchan->attr.num_subbuf;
 150                         channels[i].attr.switch_timer_interval =
 151                                 uchan->attr.switch_timer_interval;
 152                         channels[i].attr.read_timer_interval =
 153                                 uchan->attr.read_timer_interval;
 154                         channels[i].enabled = uchan->enabled;
 155                         switch (uchan->attr.output) {
 156                         case LTTNG_UST_MMAP:
 157                         default:
 158                                 channels[i].attr.output = LTTNG_EVENT_MMAP;
 159                                 break;
 160                         }
 161                         i++;
 162                 }
 163                 break;
 164         }
 165         default:
 166                 break;
 167         }
 168 }
 169
 170 /*
 171  * Create a list of ust global domain events.
 172  */
 173 static int list_lttng_ust_global_events(char *channel_name,
 174                 struct ltt_ust_domain_global *ust_global, struct lttng_event **events)
 175 {
 176         int i = 0, ret = 0;
 177         unsigned int nb_event = 0;
 178         struct lttng_ht_iter iter;
 179         struct lttng_ht_node_str *node;
 180         struct ltt_ust_channel *uchan;
 181         struct ltt_ust_event *uevent;
 182         struct lttng_event *tmp;
 183
 184         DBG("Listing UST global events for channel %s", channel_name);
 185
 186         rcu_read_lock();
 187
 188         lttng_ht_lookup(ust_global->channels, (void *)channel_name, &iter);
 189         node = lttng_ht_iter_get_node_str(&iter);
 190         if (node == NULL) {
 191                 ret = -LTTCOMM_UST_CHAN_NOT_FOUND;
 192                 goto error;
 193         }
 194
 195         uchan = caa_container_of(&node->node, struct ltt_ust_channel, node.node);
 196
 197         nb_event += lttng_ht_get_count(uchan->events);
 198
 199         if (nb_event == 0) {
 200                 ret = nb_event;
 201                 goto error;
 202         }
 203
 204         DBG3("Listing UST global %d events", nb_event);
 205
 206         tmp = zmalloc(nb_event * sizeof(struct lttng_event));
 207         if (tmp == NULL) {
 208                 ret = -LTTCOMM_FATAL;
 209                 goto error;
 210         }
 211
 212         cds_lfht_for_each_entry(uchan->events->ht, &iter.iter, uevent, node.node) {
 213                 strncpy(tmp[i].name, uevent->attr.name, LTTNG_SYMBOL_NAME_LEN);
 214                 tmp[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 215                 tmp[i].enabled = uevent->enabled;
 216
 217                 switch (uevent->attr.instrumentation) {
 218                 case LTTNG_UST_TRACEPOINT:
 219                         tmp[i].type = LTTNG_EVENT_TRACEPOINT;
 220                         break;
 221                 case LTTNG_UST_PROBE:
 222                         tmp[i].type = LTTNG_EVENT_PROBE;
 223                         break;
 224                 case LTTNG_UST_FUNCTION:
 225                         tmp[i].type = LTTNG_EVENT_FUNCTION;
 226                         break;
 227                 }
 228
 229                 tmp[i].loglevel = uevent->attr.loglevel;
 230                 switch (uevent->attr.loglevel_type) {
 231                 case LTTNG_UST_LOGLEVEL_ALL:
 232                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
 233                         break;
 234                 case LTTNG_UST_LOGLEVEL_RANGE:
 235                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_RANGE;
 236                         break;
 237                 case LTTNG_UST_LOGLEVEL_SINGLE:
 238                         tmp[i].loglevel_type = LTTNG_EVENT_LOGLEVEL_SINGLE;
 239                         break;
 240                 }
 241                 if (uevent->filter) {
 242                         tmp[i].filter = 1;
 243                 }
 244                 i++;
 245         }
 246
 247         ret = nb_event;
 248         *events = tmp;
 249
 250 error:
 251         rcu_read_unlock();
 252         return ret;
 253 }
 254
 255 /*
 256  * Fill lttng_event array of all kernel events in the channel.
 257  */
 258 static int list_lttng_kernel_events(char *channel_name,
 259                 struct ltt_kernel_session *kernel_session, struct lttng_event **events)
 260 {
 261         int i = 0, ret;
 262         unsigned int nb_event;
 263         struct ltt_kernel_event *event;
 264         struct ltt_kernel_channel *kchan;
 265
 266         kchan = trace_kernel_get_channel_by_name(channel_name, kernel_session);
 267         if (kchan == NULL) {
 268                 ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
 269                 goto error;
 270         }
 271
 272         nb_event = kchan->event_count;
 273
 274         DBG("Listing events for channel %s", kchan->channel->name);
 275
 276         if (nb_event == 0) {
 277                 ret = nb_event;
 278                 goto error;
 279         }
 280
 281         *events = zmalloc(nb_event * sizeof(struct lttng_event));
 282         if (*events == NULL) {
 283                 ret = LTTCOMM_FATAL;
 284                 goto error;
 285         }
 286
 287         /* Kernel channels */
 288         cds_list_for_each_entry(event, &kchan->events_list.head , list) {
 289                 strncpy((*events)[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
 290                 (*events)[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
 291                 (*events)[i].enabled = event->enabled;
 292
 293                 switch (event->event->instrumentation) {
 294                 case LTTNG_KERNEL_TRACEPOINT:
 295                         (*events)[i].type = LTTNG_EVENT_TRACEPOINT;
 296                         break;
 297                 case LTTNG_KERNEL_KPROBE:
 298                 case LTTNG_KERNEL_KRETPROBE:
 299                         (*events)[i].type = LTTNG_EVENT_PROBE;
 300                         memcpy(&(*events)[i].attr.probe, &event->event->u.kprobe,
 301                                         sizeof(struct lttng_kernel_kprobe));
 302                         break;
 303                 case LTTNG_KERNEL_FUNCTION:
 304                         (*events)[i].type = LTTNG_EVENT_FUNCTION;
 305                         memcpy(&((*events)[i].attr.ftrace), &event->event->u.ftrace,
 306                                         sizeof(struct lttng_kernel_function));
 307                         break;
 308                 case LTTNG_KERNEL_NOOP:
 309                         (*events)[i].type = LTTNG_EVENT_NOOP;
 310                         break;
 311                 case LTTNG_KERNEL_SYSCALL:
 312                         (*events)[i].type = LTTNG_EVENT_SYSCALL;
 313                         break;
 314                 case LTTNG_KERNEL_ALL:
 315                         assert(0);
 316                         break;
 317                 }
 318                 i++;
 319         }
 320
 321         return nb_event;
 322
 323 error:
 324         return ret;
 325 }
 326
 327 /*
 328  * Add URI so the consumer output object. Set the correct path depending on the
 329  * domain adding the default trace directory.
 330  */
 331 static int add_uri_to_consumer(struct consumer_output *consumer,
 332                 struct lttng_uri *uri, int domain, const char *session_name)
 333 {
 334         int ret = LTTCOMM_OK;
 335         const char *default_trace_dir;
 336
 337         assert(uri);
 338
 339         if (consumer == NULL) {
 340                 DBG("No consumer detected. Don't add URI. Stopping.");
 341                 ret = LTTCOMM_NO_CONSUMER;
 342                 goto error;
 343         }
 344
 345         switch (domain) {
 346         case LTTNG_DOMAIN_KERNEL:
 347                 default_trace_dir = DEFAULT_KERNEL_TRACE_DIR;
 348                 break;
 349         case LTTNG_DOMAIN_UST:
 350                 default_trace_dir = DEFAULT_UST_TRACE_DIR;
 351                 break;
 352         default:
 353                 /*
 354                  * This case is possible is we try to add the URI to the global tracing
 355                  * session consumer object which in this case there is no subdir.
 356                  */
 357                 default_trace_dir = "";
 358         }
 359
 360         switch (uri->dtype) {
 361         case LTTNG_DST_IPV4:
 362         case LTTNG_DST_IPV6:
 363                 DBG2("Setting network URI to consumer");
 364
 365                 /* Set URI into consumer output object */
 366                 ret = consumer_set_network_uri(consumer, uri);
 367                 if (ret < 0) {
 368                         ret = LTTCOMM_FATAL;
 369                         goto error;
 370                 } else if (ret == 1) {
 371                         /*
 372                          * URI was the same in the consumer so we do not append the subdir
 373                          * again so to not duplicate output dir.
 374                          */
 375                         goto error;
 376                 }
 377
 378                 if (uri->stype == LTTNG_STREAM_CONTROL && strlen(uri->subdir) == 0) {
 379                         ret = consumer_set_subdir(consumer, session_name);
 380                         if (ret < 0) {
 381                                 ret = LTTCOMM_FATAL;
 382                                 goto error;
 383                         }
 384                 }
 385
 386                 if (uri->stype == LTTNG_STREAM_CONTROL) {
 387                         /* On a new subdir, reappend the default trace dir. */
 388                         strncat(consumer->subdir, default_trace_dir,
 389                                         sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
 390                         DBG3("Append domain trace name to subdir %s", consumer->subdir);
 391                 }
 392
 393                 break;
 394         case LTTNG_DST_PATH:
 395                 DBG2("Setting trace directory path from URI to %s", uri->dst.path);
 396                 memset(consumer->dst.trace_path, 0,
 397                                 sizeof(consumer->dst.trace_path));
 398                 strncpy(consumer->dst.trace_path, uri->dst.path,
 399                                 sizeof(consumer->dst.trace_path));
 400                 /* Append default trace dir */
 401                 strncat(consumer->dst.trace_path, default_trace_dir,
 402                                 sizeof(consumer->dst.trace_path) -
 403                                 strlen(consumer->dst.trace_path) - 1);
 404                 /* Flag consumer as local. */
 405                 consumer->type = CONSUMER_DST_LOCAL;
 406                 break;
 407         }
 408
 409 error:
 410         return ret;
 411 }
 412
 413 /*
 414  * Init tracing by creating trace directory and sending fds kernel consumer.
 415  */
 416 static int init_kernel_tracing(struct ltt_kernel_session *session)
 417 {
 418         int ret = 0;
 419         struct lttng_ht_iter iter;
 420         struct consumer_socket *socket;
 421
 422         assert(session);
 423
 424         if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
 425                 cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
 426                                 socket, node.node) {
 427                         /* Code flow error */
 428                         assert(socket->fd >= 0);
 429
 430                         pthread_mutex_lock(socket->lock);
 431                         ret = kernel_consumer_send_session(socket->fd, session);
 432                         pthread_mutex_unlock(socket->lock);
 433                         if (ret < 0) {
 434                                 ret = LTTCOMM_KERN_CONSUMER_FAIL;
 435                                 goto error;
 436                         }
 437                 }
 438         }
 439
 440 error:
 441         return ret;
 442 }
 443
 444 /*
 445  * Create a socket to the relayd using the URI.
 446  *
 447  * On success, the relayd_sock pointer is set to the created socket.
 448  * Else, it's stays untouched and a lttcomm error code is returned.
 449  */
 450 static int create_connect_relayd(struct consumer_output *output,
 451                 const char *session_name, struct lttng_uri *uri,
 452                 struct lttcomm_sock **relayd_sock)
 453 {
 454         int ret;
 455         struct lttcomm_sock *sock;
 456
 457         /* Create socket object from URI */
 458         sock = lttcomm_alloc_sock_from_uri(uri);
 459         if (sock == NULL) {
 460                 ret = LTTCOMM_FATAL;
 461                 goto error;
 462         }
 463
 464         ret = lttcomm_create_sock(sock);
 465         if (ret < 0) {
 466                 ret = LTTCOMM_FATAL;
 467                 goto error;
 468         }
 469
 470         /* Connect to relayd so we can proceed with a session creation. */
 471         ret = relayd_connect(sock);
 472         if (ret < 0) {
 473                 ERR("Unable to reach lttng-relayd");
 474                 ret = LTTCOMM_RELAYD_SESSION_FAIL;
 475                 goto free_sock;
 476         }
 477
 478         /* Create socket for control stream. */
 479         if (uri->stype == LTTNG_STREAM_CONTROL) {
 480                 DBG3("Creating relayd stream socket from URI");
 481
 482                 /* Check relayd version */
 483                 ret = relayd_version_check(sock, RELAYD_VERSION_COMM_MAJOR,
 484                                 RELAYD_VERSION_COMM_MINOR);
 485                 if (ret < 0) {
 486                         ret = LTTCOMM_RELAYD_VERSION_FAIL;
 487                         goto close_sock;
 488                 }
 489         } else if (uri->stype == LTTNG_STREAM_DATA) {
 490                 DBG3("Creating relayd data socket from URI");
 491         } else {
 492                 /* Command is not valid */
 493                 ERR("Relayd invalid stream type: %d", uri->stype);
 494                 ret = LTTCOMM_INVALID;
 495                 goto close_sock;
 496         }
 497
 498         *relayd_sock = sock;
 499
 500         return LTTCOMM_OK;
 501
 502 close_sock:
 503         if (sock) {
 504                 (void) relayd_close(sock);
 505         }
 506 free_sock:
 507         if (sock) {
 508                 lttcomm_destroy_sock(sock);
 509         }
 510 error:
 511         return ret;
 512 }
 513
 514 /*
 515  * Connect to the relayd using URI and send the socket to the right consumer.
 516  */
 517 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
 518                 struct lttng_uri *relayd_uri, struct consumer_output *consumer,
 519                 int consumer_fd)
 520 {
 521         int ret;
 522         struct lttcomm_sock *sock = NULL;
 523
 524         /* Set the network sequence index if not set. */
 525         if (consumer->net_seq_index == -1) {
 526                 /*
 527                  * Increment net_seq_idx because we are about to transfer the
 528                  * new relayd socket to the consumer.
 529                  */
 530                 uatomic_inc(&relayd_net_seq_idx);
 531                 /* Assign unique key so the consumer can match streams */
 532                 uatomic_set(&consumer->net_seq_index,
 533                                 uatomic_read(&relayd_net_seq_idx));
 534         }
 535
 536         /* Connect to relayd and make version check if uri is the control. */
 537         ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
 538         if (ret != LTTCOMM_OK) {
 539                 goto close_sock;
 540         }
 541
 542         /* If the control socket is connected, network session is ready */
 543         if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
 544                 session->net_handle = 1;
 545         }
 546
 547         /* Send relayd socket to consumer. */
 548         ret = consumer_send_relayd_socket(consumer_fd, sock,
 549                         consumer, relayd_uri->stype);
 550         if (ret < 0) {
 551                 ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
 552                 goto close_sock;
 553         }
 554
 555         ret = LTTCOMM_OK;
 556
 557         /*
 558          * Close socket which was dup on the consumer side. The session daemon does
 559          * NOT keep track of the relayd socket(s) once transfer to the consumer.
 560          */
 561
 562 close_sock:
 563         if (sock) {
 564                 (void) relayd_close(sock);
 565                 lttcomm_destroy_sock(sock);
 566         }
 567
 568         return ret;
 569 }
 570
 571 /*
 572  * Send both relayd sockets to a specific consumer and domain.  This is a
 573  * helper function to facilitate sending the information to the consumer for a
 574  * session.
 575  */
 576 static int send_consumer_relayd_sockets(int domain,
 577                 struct ltt_session *session, struct consumer_output *consumer, int fd)
 578 {
 579         int ret;
 580
 581         assert(session);
 582         assert(consumer);
 583
 584         /* Don't resend the sockets to the consumer. */
 585         if (consumer->dst.net.relayd_socks_sent) {
 586                 ret = LTTCOMM_OK;
 587                 goto error;
 588         }
 589
 590         /* Sending control relayd socket. */
 591         ret = send_consumer_relayd_socket(domain, session,
 592                         &consumer->dst.net.control, consumer, fd);
 593         if (ret != LTTCOMM_OK) {
 594                 goto error;
 595         }
 596
 597         /* Sending data relayd socket. */
 598         ret = send_consumer_relayd_socket(domain, session,
 599                         &consumer->dst.net.data, consumer, fd);
 600         if (ret != LTTCOMM_OK) {
 601                 goto error;
 602         }
 603
 604         /* Flag that all relayd sockets were sent to the consumer. */
 605         consumer->dst.net.relayd_socks_sent = 1;
 606
 607 error:
 608         return ret;
 609 }
 610
 611 /*
 612  * Setup relayd connections for a tracing session. First creates the socket to
 613  * the relayd and send them to the right domain consumer. Consumer type MUST be
 614  * network.
 615  */
 616 static int setup_relayd(struct ltt_session *session)
 617 {
 618         int ret = LTTCOMM_OK;
 619         struct ltt_ust_session *usess;
 620         struct ltt_kernel_session *ksess;
 621         struct consumer_socket *socket;
 622         struct lttng_ht_iter iter;
 623
 624         assert(session);
 625
 626         usess = session->ust_session;
 627         ksess = session->kernel_session;
 628
 629         DBG2("Setting relayd for session %s", session->name);
 630
 631         if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 632                         && usess->consumer->enabled) {
 633                 /* For each consumer socket, send relayd sockets */
 634                 cds_lfht_for_each_entry(usess->consumer->socks->ht, &iter.iter,
 635                                 socket, node.node) {
 636                         /* Code flow error */
 637                         assert(socket->fd >= 0);
 638
 639                         pthread_mutex_lock(socket->lock);
 640                         send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
 641                                         usess->consumer, socket->fd);
 642                         pthread_mutex_unlock(socket->lock);
 643                         if (ret != LTTCOMM_OK) {
 644                                 goto error;
 645                         }
 646                 }
 647         }
 648
 649         if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
 650                         && ksess->consumer->enabled) {
 651                 cds_lfht_for_each_entry(ksess->consumer->socks->ht, &iter.iter,
 652                                 socket, node.node) {
 653                         /* Code flow error */
 654                         assert(socket->fd >= 0);
 655
 656                         pthread_mutex_lock(socket->lock);
 657                         send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
 658                                         ksess->consumer, socket->fd);
 659                         pthread_mutex_unlock(socket->lock);
 660                         if (ret != LTTCOMM_OK) {
 661                                 goto error;
 662                         }
 663                 }
 664         }
 665
 666 error:
 667         return ret;
 668 }
 669
 670 /*
 671  * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
 672  */
 673 int cmd_disable_channel(struct ltt_session *session, int domain,
 674                 char *channel_name)
 675 {
 676         int ret;
 677         struct ltt_ust_session *usess;
 678
 679         usess = session->ust_session;
 680
 681         switch (domain) {
 682         case LTTNG_DOMAIN_KERNEL:
 683         {
 684                 ret = channel_kernel_disable(session->kernel_session,
 685                                 channel_name);
 686                 if (ret != LTTCOMM_OK) {
 687                         goto error;
 688                 }
 689
 690                 kernel_wait_quiescent(kernel_tracer_fd);
 691                 break;
 692         }
 693         case LTTNG_DOMAIN_UST:
 694         {
 695                 struct ltt_ust_channel *uchan;
 696                 struct lttng_ht *chan_ht;
 697
 698                 chan_ht = usess->domain_global.channels;
 699
 700                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 701                 if (uchan == NULL) {
 702                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
 703                         goto error;
 704                 }
 705
 706                 ret = channel_ust_disable(usess, domain, uchan);
 707                 if (ret != LTTCOMM_OK) {
 708                         goto error;
 709                 }
 710                 break;
 711         }
 712 #if 0
 713         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 714         case LTTNG_DOMAIN_UST_EXEC_NAME:
 715         case LTTNG_DOMAIN_UST_PID:
 716 #endif
 717         default:
 718                 ret = LTTCOMM_UNKNOWN_DOMAIN;
 719                 goto error;
 720         }
 721
 722         ret = LTTCOMM_OK;
 723
 724 error:
 725         return ret;
 726 }
 727
 728 /*
 729  * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
 730  *
 731  * The wpipe arguments is used as a notifier for the kernel thread.
 732  */
 733 int cmd_enable_channel(struct ltt_session *session,
 734                 int domain, struct lttng_channel *attr, int wpipe)
 735 {
 736         int ret;
 737         struct ltt_ust_session *usess = session->ust_session;
 738         struct lttng_ht *chan_ht;
 739
 740         assert(session);
 741         assert(attr);
 742
 743         DBG("Enabling channel %s for session %s", attr->name, session->name);
 744
 745         switch (domain) {
 746         case LTTNG_DOMAIN_KERNEL:
 747         {
 748                 struct ltt_kernel_channel *kchan;
 749
 750                 /* Mandatory for a kernel channel. */
 751                 assert(wpipe > 0);
 752
 753                 kchan = trace_kernel_get_channel_by_name(attr->name,
 754                                 session->kernel_session);
 755                 if (kchan == NULL) {
 756                         ret = channel_kernel_create(session->kernel_session, attr, wpipe);
 757                 } else {
 758                         ret = channel_kernel_enable(session->kernel_session, kchan);
 759                 }
 760
 761                 if (ret != LTTCOMM_OK) {
 762                         goto error;
 763                 }
 764
 765                 kernel_wait_quiescent(kernel_tracer_fd);
 766                 break;
 767         }
 768         case LTTNG_DOMAIN_UST:
 769         {
 770                 struct ltt_ust_channel *uchan;
 771
 772                 chan_ht = usess->domain_global.channels;
 773
 774                 uchan = trace_ust_find_channel_by_name(chan_ht, attr->name);
 775                 if (uchan == NULL) {
 776                         ret = channel_ust_create(usess, domain, attr);
 777                 } else {
 778                         ret = channel_ust_enable(usess, domain, uchan);
 779                 }
 780                 break;
 781         }
 782 #if 0
 783         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 784         case LTTNG_DOMAIN_UST_EXEC_NAME:
 785         case LTTNG_DOMAIN_UST_PID:
 786 #endif
 787         default:
 788                 ret = LTTCOMM_UNKNOWN_DOMAIN;
 789                 goto error;
 790         }
 791
 792 error:
 793         return ret;
 794 }
 795
 796
 797 /*
 798  * Command LTTNG_DISABLE_EVENT processed by the client thread.
 799  */
 800 int cmd_disable_event(struct ltt_session *session, int domain,
 801                 char *channel_name, char *event_name)
 802 {
 803         int ret;
 804
 805         switch (domain) {
 806         case LTTNG_DOMAIN_KERNEL:
 807         {
 808                 struct ltt_kernel_channel *kchan;
 809                 struct ltt_kernel_session *ksess;
 810
 811                 ksess = session->kernel_session;
 812
 813                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 814                 if (kchan == NULL) {
 815                         ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
 816                         goto error;
 817                 }
 818
 819                 ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
 820                 if (ret != LTTCOMM_OK) {
 821                         goto error;
 822                 }
 823
 824                 kernel_wait_quiescent(kernel_tracer_fd);
 825                 break;
 826         }
 827         case LTTNG_DOMAIN_UST:
 828         {
 829                 struct ltt_ust_channel *uchan;
 830                 struct ltt_ust_session *usess;
 831
 832                 usess = session->ust_session;
 833
 834                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 835                                 channel_name);
 836                 if (uchan == NULL) {
 837                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
 838                         goto error;
 839                 }
 840
 841                 ret = event_ust_disable_tracepoint(usess, domain, uchan, event_name);
 842                 if (ret != LTTCOMM_OK) {
 843                         goto error;
 844                 }
 845
 846                 DBG3("Disable UST event %s in channel %s completed", event_name,
 847                                 channel_name);
 848                 break;
 849         }
 850 #if 0
 851         case LTTNG_DOMAIN_UST_EXEC_NAME:
 852         case LTTNG_DOMAIN_UST_PID:
 853         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 854 #endif
 855         default:
 856                 ret = LTTCOMM_UND;
 857                 goto error;
 858         }
 859
 860         ret = LTTCOMM_OK;
 861
 862 error:
 863         return ret;
 864 }
 865
 866 /*
 867  * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
 868  */
 869 int cmd_disable_event_all(struct ltt_session *session, int domain,
 870                 char *channel_name)
 871 {
 872         int ret;
 873
 874         switch (domain) {
 875         case LTTNG_DOMAIN_KERNEL:
 876         {
 877                 struct ltt_kernel_session *ksess;
 878                 struct ltt_kernel_channel *kchan;
 879
 880                 ksess = session->kernel_session;
 881
 882                 kchan = trace_kernel_get_channel_by_name(channel_name, ksess);
 883                 if (kchan == NULL) {
 884                         ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
 885                         goto error;
 886                 }
 887
 888                 ret = event_kernel_disable_all(ksess, kchan);
 889                 if (ret != LTTCOMM_OK) {
 890                         goto error;
 891                 }
 892
 893                 kernel_wait_quiescent(kernel_tracer_fd);
 894                 break;
 895         }
 896         case LTTNG_DOMAIN_UST:
 897         {
 898                 struct ltt_ust_session *usess;
 899                 struct ltt_ust_channel *uchan;
 900
 901                 usess = session->ust_session;
 902
 903                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
 904                                 channel_name);
 905                 if (uchan == NULL) {
 906                         ret = LTTCOMM_UST_CHAN_NOT_FOUND;
 907                         goto error;
 908                 }
 909
 910                 ret = event_ust_disable_all_tracepoints(usess, domain, uchan);
 911                 if (ret != 0) {
 912                         goto error;
 913                 }
 914
 915                 DBG3("Disable all UST events in channel %s completed", channel_name);
 916
 917                 break;
 918         }
 919 #if 0
 920         case LTTNG_DOMAIN_UST_EXEC_NAME:
 921         case LTTNG_DOMAIN_UST_PID:
 922         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 923 #endif
 924         default:
 925                 ret = LTTCOMM_UND;
 926                 goto error;
 927         }
 928
 929         ret = LTTCOMM_OK;
 930
 931 error:
 932         return ret;
 933 }
 934
 935 /*
 936  * Command LTTNG_ADD_CONTEXT processed by the client thread.
 937  */
 938 int cmd_add_context(struct ltt_session *session, int domain,
 939                 char *channel_name, char *event_name, struct lttng_event_context *ctx)
 940 {
 941         int ret;
 942
 943         switch (domain) {
 944         case LTTNG_DOMAIN_KERNEL:
 945                 /* Add kernel context to kernel tracer */
 946                 ret = context_kernel_add(session->kernel_session, ctx,
 947                                 event_name, channel_name);
 948                 if (ret != LTTCOMM_OK) {
 949                         goto error;
 950                 }
 951                 break;
 952         case LTTNG_DOMAIN_UST:
 953         {
 954                 struct ltt_ust_session *usess = session->ust_session;
 955
 956                 assert(usess);
 957
 958                 ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
 959                 if (ret != LTTCOMM_OK) {
 960                         goto error;
 961                 }
 962                 break;
 963         }
 964 #if 0
 965         case LTTNG_DOMAIN_UST_EXEC_NAME:
 966         case LTTNG_DOMAIN_UST_PID:
 967         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
 968 #endif
 969         default:
 970                 ret = LTTCOMM_UND;
 971                 goto error;
 972         }
 973
 974         ret = LTTCOMM_OK;
 975
 976 error:
 977         return ret;
 978 }
 979
 980 /*
 981  * Command LTTNG_SET_FILTER processed by the client thread.
 982  */
 983 int cmd_set_filter(struct ltt_session *session, int domain,
 984                 char *channel_name, char *event_name,
 985                 struct lttng_filter_bytecode *bytecode)
 986 {
 987         int ret;
 988
 989         switch (domain) {
 990         case LTTNG_DOMAIN_KERNEL:
 991                 ret = LTTCOMM_FATAL;
 992                 break;
 993         case LTTNG_DOMAIN_UST:
 994         {
 995                 struct ltt_ust_session *usess = session->ust_session;
 996
 997                 ret = filter_ust_set(usess, domain, bytecode, event_name, channel_name);
 998                 if (ret != LTTCOMM_OK) {
 999                         goto error;
1000                 }
1001                 break;
1002         }
1003 #if 0
1004         case LTTNG_DOMAIN_UST_EXEC_NAME:
1005         case LTTNG_DOMAIN_UST_PID:
1006         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1007 #endif
1008         default:
1009                 ret = LTTCOMM_UND;
1010                 goto error;
1011         }
1012
1013         ret = LTTCOMM_OK;
1014
1015 error:
1016         return ret;
1017
1018 }
1019
1020
1021 /*
1022  * Command LTTNG_ENABLE_EVENT processed by the client thread.
1023  */
1024 int cmd_enable_event(struct ltt_session *session, int domain,
1025                 char *channel_name, struct lttng_event *event, int wpipe)
1026 {
1027         int ret;
1028         struct lttng_channel *attr;
1029
1030         assert(session);
1031         assert(event);
1032         assert(channel_name);
1033
1034         switch (domain) {
1035         case LTTNG_DOMAIN_KERNEL:
1036         {
1037                 struct ltt_kernel_channel *kchan;
1038
1039                 kchan = trace_kernel_get_channel_by_name(channel_name,
1040                                 session->kernel_session);
1041                 if (kchan == NULL) {
1042                         attr = channel_new_default_attr(domain);
1043                         if (attr == NULL) {
1044                                 ret = LTTCOMM_FATAL;
1045                                 goto error;
1046                         }
1047                         strncpy(attr->name, channel_name, sizeof(attr->name));
1048
1049                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1050                         if (ret != LTTCOMM_OK) {
1051                                 free(attr);
1052                                 goto error;
1053                         }
1054                         free(attr);
1055                 }
1056
1057                 /* Get the newly created kernel channel pointer */
1058                 kchan = trace_kernel_get_channel_by_name(channel_name,
1059                                 session->kernel_session);
1060                 if (kchan == NULL) {
1061                         /* This sould not happen... */
1062                         ret = LTTCOMM_FATAL;
1063                         goto error;
1064                 }
1065
1066                 ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
1067                                 event);
1068                 if (ret != LTTCOMM_OK) {
1069                         goto error;
1070                 }
1071
1072                 kernel_wait_quiescent(kernel_tracer_fd);
1073                 break;
1074         }
1075         case LTTNG_DOMAIN_UST:
1076         {
1077                 struct ltt_ust_channel *uchan;
1078                 struct ltt_ust_session *usess = session->ust_session;
1079
1080                 assert(usess);
1081
1082                 /* Get channel from global UST domain */
1083                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1084                                 channel_name);
1085                 if (uchan == NULL) {
1086                         /* Create default channel */
1087                         attr = channel_new_default_attr(domain);
1088                         if (attr == NULL) {
1089                                 ret = LTTCOMM_FATAL;
1090                                 goto error;
1091                         }
1092                         strncpy(attr->name, channel_name, sizeof(attr->name));
1093
1094                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1095                         if (ret != LTTCOMM_OK) {
1096                                 free(attr);
1097                                 goto error;
1098                         }
1099                         free(attr);
1100
1101                         /* Get the newly created channel reference back */
1102                         uchan = trace_ust_find_channel_by_name(
1103                                         usess->domain_global.channels, channel_name);
1104                         assert(uchan);
1105                 }
1106
1107                 /* At this point, the session and channel exist on the tracer */
1108                 ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
1109                 if (ret != LTTCOMM_OK) {
1110                         goto error;
1111                 }
1112                 break;
1113         }
1114 #if 0
1115         case LTTNG_DOMAIN_UST_EXEC_NAME:
1116         case LTTNG_DOMAIN_UST_PID:
1117         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1118 #endif
1119         default:
1120                 ret = LTTCOMM_UND;
1121                 goto error;
1122         }
1123
1124         ret = LTTCOMM_OK;
1125
1126 error:
1127         return ret;
1128 }
1129
1130 /*
1131  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
1132  */
1133 int cmd_enable_event_all(struct ltt_session *session, int domain,
1134                 char *channel_name, int event_type, int wpipe)
1135 {
1136         int ret;
1137         struct lttng_channel *attr;
1138
1139         assert(session);
1140         assert(channel_name);
1141
1142         switch (domain) {
1143         case LTTNG_DOMAIN_KERNEL:
1144         {
1145                 struct ltt_kernel_channel *kchan;
1146
1147                 assert(session->kernel_session);
1148
1149                 kchan = trace_kernel_get_channel_by_name(channel_name,
1150                                 session->kernel_session);
1151                 if (kchan == NULL) {
1152                         /* Create default channel */
1153                         attr = channel_new_default_attr(domain);
1154                         if (attr == NULL) {
1155                                 ret = LTTCOMM_FATAL;
1156                                 goto error;
1157                         }
1158                         strncpy(attr->name, channel_name, sizeof(attr->name));
1159
1160                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1161                         if (ret != LTTCOMM_OK) {
1162                                 free(attr);
1163                                 goto error;
1164                         }
1165                         free(attr);
1166
1167                         /* Get the newly created kernel channel pointer */
1168                         kchan = trace_kernel_get_channel_by_name(channel_name,
1169                                         session->kernel_session);
1170                         assert(kchan);
1171                 }
1172
1173                 switch (event_type) {
1174                 case LTTNG_EVENT_SYSCALL:
1175                         ret = event_kernel_enable_all_syscalls(session->kernel_session,
1176                                         kchan, kernel_tracer_fd);
1177                         break;
1178                 case LTTNG_EVENT_TRACEPOINT:
1179                         /*
1180                          * This call enables all LTTNG_KERNEL_TRACEPOINTS and
1181                          * events already registered to the channel.
1182                          */
1183                         ret = event_kernel_enable_all_tracepoints(session->kernel_session,
1184                                         kchan, kernel_tracer_fd);
1185                         break;
1186                 case LTTNG_EVENT_ALL:
1187                         /* Enable syscalls and tracepoints */
1188                         ret = event_kernel_enable_all(session->kernel_session,
1189                                         kchan, kernel_tracer_fd);
1190                         break;
1191                 default:
1192                         ret = LTTCOMM_KERN_ENABLE_FAIL;
1193                         goto error;
1194                 }
1195
1196                 /* Manage return value */
1197                 if (ret != LTTCOMM_OK) {
1198                         goto error;
1199                 }
1200
1201                 kernel_wait_quiescent(kernel_tracer_fd);
1202                 break;
1203         }
1204         case LTTNG_DOMAIN_UST:
1205         {
1206                 struct ltt_ust_channel *uchan;
1207                 struct ltt_ust_session *usess = session->ust_session;
1208
1209                 assert(usess);
1210
1211                 /* Get channel from global UST domain */
1212                 uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
1213                                 channel_name);
1214                 if (uchan == NULL) {
1215                         /* Create default channel */
1216                         attr = channel_new_default_attr(domain);
1217                         if (attr == NULL) {
1218                                 ret = LTTCOMM_FATAL;
1219                                 goto error;
1220                         }
1221                         strncpy(attr->name, channel_name, sizeof(attr->name));
1222
1223                         ret = cmd_enable_channel(session, domain, attr, wpipe);
1224                         if (ret != LTTCOMM_OK) {
1225                                 free(attr);
1226                                 goto error;
1227                         }
1228                         free(attr);
1229
1230                         /* Get the newly created channel reference back */
1231                         uchan = trace_ust_find_channel_by_name(
1232                                         usess->domain_global.channels, channel_name);
1233                         assert(uchan);
1234                 }
1235
1236                 /* At this point, the session and channel exist on the tracer */
1237
1238                 switch (event_type) {
1239                 case LTTNG_EVENT_ALL:
1240                 case LTTNG_EVENT_TRACEPOINT:
1241                         ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
1242                         if (ret != LTTCOMM_OK) {
1243                                 goto error;
1244                         }
1245                         break;
1246                 default:
1247                         ret = LTTCOMM_UST_ENABLE_FAIL;
1248                         goto error;
1249                 }
1250
1251                 /* Manage return value */
1252                 if (ret != LTTCOMM_OK) {
1253                         goto error;
1254                 }
1255
1256                 break;
1257         }
1258 #if 0
1259         case LTTNG_DOMAIN_UST_EXEC_NAME:
1260         case LTTNG_DOMAIN_UST_PID:
1261         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
1262 #endif
1263         default:
1264                 ret = LTTCOMM_UND;
1265                 goto error;
1266         }
1267
1268         ret = LTTCOMM_OK;
1269
1270 error:
1271         return ret;
1272 }
1273
1274
1275 /*
1276  * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
1277  */
1278 ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
1279 {
1280         int ret;
1281         ssize_t nb_events = 0;
1282
1283         switch (domain) {
1284         case LTTNG_DOMAIN_KERNEL:
1285                 nb_events = kernel_list_events(kernel_tracer_fd, events);
1286                 if (nb_events < 0) {
1287                         ret = LTTCOMM_KERN_LIST_FAIL;
1288                         goto error;
1289                 }
1290                 break;
1291         case LTTNG_DOMAIN_UST:
1292                 nb_events = ust_app_list_events(events);
1293                 if (nb_events < 0) {
1294                         ret = LTTCOMM_UST_LIST_FAIL;
1295                         goto error;
1296                 }
1297                 break;
1298         default:
1299                 ret = LTTCOMM_UND;
1300                 goto error;
1301         }
1302
1303         return nb_events;
1304
1305 error:
1306         /* Return negative value to differentiate return code */
1307         return -ret;
1308 }
1309
1310 /*
1311  * Command LTTNG_LIST_TRACEPOINT_FIELDS processed by the client thread.
1312  */
1313 ssize_t cmd_list_tracepoint_fields(int domain,
1314                 struct lttng_event_field **fields)
1315 {
1316         int ret;
1317         ssize_t nb_fields = 0;
1318
1319         switch (domain) {
1320         case LTTNG_DOMAIN_UST:
1321                 nb_fields = ust_app_list_event_fields(fields);
1322                 if (nb_fields < 0) {
1323                         ret = LTTCOMM_UST_LIST_FAIL;
1324                         goto error;
1325                 }
1326                 break;
1327         case LTTNG_DOMAIN_KERNEL:
1328         default:        /* fall-through */
1329                 ret = LTTCOMM_UND;
1330                 goto error;
1331         }
1332
1333         return nb_fields;
1334
1335 error:
1336         /* Return negative value to differentiate return code */
1337         return -ret;
1338 }
1339
1340 /*
1341  * Command LTTNG_START_TRACE processed by the client thread.
1342  */
1343 int cmd_start_trace(struct ltt_session *session)
1344 {
1345         int ret;
1346         struct ltt_kernel_session *ksession;
1347         struct ltt_ust_session *usess;
1348         struct ltt_kernel_channel *kchan;
1349
1350         assert(session);
1351
1352         /* Ease our life a bit ;) */
1353         ksession = session->kernel_session;
1354         usess = session->ust_session;
1355
1356         if (session->enabled) {
1357                 /* Already started. */
1358                 ret = LTTCOMM_TRACE_ALREADY_STARTED;
1359                 goto error;
1360         }
1361
1362         session->enabled = 1;
1363
1364         ret = setup_relayd(session);
1365         if (ret != LTTCOMM_OK) {
1366                 ERR("Error setting up relayd for session %s", session->name);
1367                 goto error;
1368         }
1369
1370         /* Kernel tracing */
1371         if (ksession != NULL) {
1372                 /* Open kernel metadata */
1373                 if (ksession->metadata == NULL) {
1374                         ret = kernel_open_metadata(ksession);
1375                         if (ret < 0) {
1376                                 ret = LTTCOMM_KERN_META_FAIL;
1377                                 goto error;
1378                         }
1379                 }
1380
1381                 /* Open kernel metadata stream */
1382                 if (ksession->metadata_stream_fd < 0) {
1383                         ret = kernel_open_metadata_stream(ksession);
1384                         if (ret < 0) {
1385                                 ERR("Kernel create metadata stream failed");
1386                                 ret = LTTCOMM_KERN_STREAM_FAIL;
1387                                 goto error;
1388                         }
1389                 }
1390
1391                 /* For each channel */
1392                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1393                         if (kchan->stream_count == 0) {
1394                                 ret = kernel_open_channel_stream(kchan);
1395                                 if (ret < 0) {
1396                                         ret = LTTCOMM_KERN_STREAM_FAIL;
1397                                         goto error;
1398                                 }
1399                                 /* Update the stream global counter */
1400                                 ksession->stream_count_global += ret;
1401                         }
1402                 }
1403
1404                 /* Setup kernel consumer socket and send fds to it */
1405                 ret = init_kernel_tracing(ksession);
1406                 if (ret < 0) {
1407                         ret = LTTCOMM_KERN_START_FAIL;
1408                         goto error;
1409                 }
1410
1411                 /* This start the kernel tracing */
1412                 ret = kernel_start_session(ksession);
1413                 if (ret < 0) {
1414                         ret = LTTCOMM_KERN_START_FAIL;
1415                         goto error;
1416                 }
1417
1418                 /* Quiescent wait after starting trace */
1419                 kernel_wait_quiescent(kernel_tracer_fd);
1420         }
1421
1422         /* Flag session that trace should start automatically */
1423         if (usess) {
1424                 usess->start_trace = 1;
1425
1426                 ret = ust_app_start_trace_all(usess);
1427                 if (ret < 0) {
1428                         ret = LTTCOMM_UST_START_FAIL;
1429                         goto error;
1430                 }
1431         }
1432
1433         ret = LTTCOMM_OK;
1434
1435 error:
1436         return ret;
1437 }
1438
1439 /*
1440  * Command LTTNG_STOP_TRACE processed by the client thread.
1441  */
1442 int cmd_stop_trace(struct ltt_session *session)
1443 {
1444         int ret;
1445         struct ltt_kernel_channel *kchan;
1446         struct ltt_kernel_session *ksession;
1447         struct ltt_ust_session *usess;
1448
1449         assert(session);
1450
1451         /* Short cut */
1452         ksession = session->kernel_session;
1453         usess = session->ust_session;
1454
1455         if (!session->enabled) {
1456                 ret = LTTCOMM_TRACE_ALREADY_STOPPED;
1457                 goto error;
1458         }
1459
1460         session->enabled = 0;
1461
1462         /* Kernel tracer */
1463         if (ksession) {
1464                 DBG("Stop kernel tracing");
1465
1466                 /* Flush metadata if exist */
1467                 if (ksession->metadata_stream_fd >= 0) {
1468                         ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
1469                         if (ret < 0) {
1470                                 ERR("Kernel metadata flush failed");
1471                         }
1472                 }
1473
1474                 /* Flush all buffers before stopping */
1475                 cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
1476                         ret = kernel_flush_buffer(kchan);
1477                         if (ret < 0) {
1478                                 ERR("Kernel flush buffer error");
1479                         }
1480                 }
1481
1482                 ret = kernel_stop_session(ksession);
1483                 if (ret < 0) {
1484                         ret = LTTCOMM_KERN_STOP_FAIL;
1485                         goto error;
1486                 }
1487
1488                 kernel_wait_quiescent(kernel_tracer_fd);
1489         }
1490
1491         if (usess) {
1492                 usess->start_trace = 0;
1493
1494                 ret = ust_app_stop_trace_all(usess);
1495                 if (ret < 0) {
1496                         ret = LTTCOMM_UST_STOP_FAIL;
1497                         goto error;
1498                 }
1499         }
1500
1501         ret = LTTCOMM_OK;
1502
1503 error:
1504         return ret;
1505 }
1506
1507 /*
1508  * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
1509  */
1510 int cmd_set_consumer_uri(int domain, struct ltt_session *session,
1511                 size_t nb_uri, struct lttng_uri *uris)
1512 {
1513         int ret, i;
1514         struct ltt_kernel_session *ksess = session->kernel_session;
1515         struct ltt_ust_session *usess = session->ust_session;
1516         struct consumer_output *consumer = NULL;
1517
1518         assert(session);
1519         assert(uris);
1520         assert(nb_uri > 0);
1521
1522         /* Can't enable consumer after session started. */
1523         if (session->enabled) {
1524                 ret = LTTCOMM_TRACE_ALREADY_STARTED;
1525                 goto error;
1526         }
1527
1528         if (!session->start_consumer) {
1529                 ret = LTTCOMM_NO_CONSUMER;
1530                 goto error;
1531         }
1532
1533         /*
1534          * This case switch makes sure the domain session has a temporary consumer
1535          * so the URL can be set.
1536          */
1537         switch (domain) {
1538         case 0:
1539                 /* Code flow error. A session MUST always have a consumer object */
1540                 assert(session->consumer);
1541                 /*
1542                  * The URL will be added to the tracing session consumer instead of a
1543                  * specific domain consumer.
1544                  */
1545                 consumer = session->consumer;
1546                 break;
1547         case LTTNG_DOMAIN_KERNEL:
1548                 /* Code flow error if we don't have a kernel session here. */
1549                 assert(ksess);
1550
1551                 /* Create consumer output if none exists */
1552                 consumer = ksess->tmp_consumer;
1553                 if (consumer == NULL) {
1554                         consumer = consumer_copy_output(ksess->consumer);
1555                         if (consumer == NULL) {
1556                                 ret = LTTCOMM_FATAL;
1557                                 goto error;
1558                         }
1559                         /* Trash the consumer subdir, we are about to set a new one. */
1560                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1561                         ksess->tmp_consumer = consumer;
1562                 }
1563
1564                 break;
1565         case LTTNG_DOMAIN_UST:
1566                 /* Code flow error if we don't have a kernel session here. */
1567                 assert(usess);
1568
1569                 /* Create consumer output if none exists */
1570                 consumer = usess->tmp_consumer;
1571                 if (consumer == NULL) {
1572                         consumer = consumer_copy_output(usess->consumer);
1573                         if (consumer == NULL) {
1574                                 ret = LTTCOMM_FATAL;
1575                                 goto error;
1576                         }
1577                         /* Trash the consumer subdir, we are about to set a new one. */
1578                         memset(consumer->subdir, 0, sizeof(consumer->subdir));
1579                         usess->tmp_consumer = consumer;
1580                 }
1581
1582                 break;
1583         }
1584
1585         for (i = 0; i < nb_uri; i++) {
1586                 struct consumer_socket *socket;
1587                 struct lttng_ht_iter iter;
1588
1589                 ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
1590                 if (ret < 0) {
1591                         goto error;
1592                 }
1593
1594                 /*
1595                  * Don't send relayd socket if URI is NOT remote or if the relayd
1596                  * sockets for the session are already sent.
1597                  */
1598                 if (uris[i].dtype == LTTNG_DST_PATH ||
1599                                 consumer->dst.net.relayd_socks_sent) {
1600                         continue;
1601                 }
1602
1603                 /* Try to send relayd URI to the consumer if exist. */
1604                 rcu_read_lock();
1605                 cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
1606                                 socket, node.node) {
1607
1608                         /* A socket in the HT should never have a negative fd */
1609                         assert(socket->fd >= 0);
1610
1611                         pthread_mutex_lock(socket->lock);
1612                         ret = send_consumer_relayd_socket(domain, session, &uris[i],
1613                                         consumer, socket->fd);
1614                         pthread_mutex_unlock(socket->lock);
1615                         if (ret != LTTCOMM_OK) {
1616                                 rcu_read_unlock();
1617                                 goto error;
1618                         }
1619                 }
1620                 rcu_read_unlock();
1621         }
1622
1623         /* All good! */
1624         ret = LTTCOMM_OK;
1625
1626 error:
1627         return ret;
1628 }
1629
1630 /*
1631  * Command LTTNG_CREATE_SESSION processed by the client thread.
1632  */
1633 int cmd_create_session_uri(char *name, struct lttng_uri *uris,
1634                 size_t nb_uri, lttng_sock_cred *creds)
1635 {
1636         int ret;
1637         char *path = NULL;
1638         struct ltt_session *session;
1639
1640         assert(name);
1641
1642         /*
1643          * Verify if the session already exist
1644          *
1645          * XXX: There is no need for the session lock list here since the caller
1646          * (process_client_msg) is holding it. We might want to change that so a
1647          * single command does not lock the entire session list.
1648          */
1649         session = session_find_by_name(name);
1650         if (session != NULL) {
1651                 ret = LTTCOMM_EXIST_SESS;
1652                 goto find_error;
1653         }
1654
1655         /* Create tracing session in the registry */
1656         ret = session_create(name, path, LTTNG_SOCK_GET_UID_CRED(creds),
1657                         LTTNG_SOCK_GET_GID_CRED(creds));
1658         if (ret != LTTCOMM_OK) {
1659                 goto session_error;
1660         }
1661
1662         /*
1663          * Get the newly created session pointer back
1664          *
1665          * XXX: There is no need for the session lock list here since the caller
1666          * (process_client_msg) is holding it. We might want to change that so a
1667          * single command does not lock the entire session list.
1668          */
1669         session = session_find_by_name(name);
1670         assert(session);
1671
1672         /* Create default consumer output for the session not yet created. */
1673         session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
1674         if (session->consumer == NULL) {
1675                 ret = LTTCOMM_FATAL;
1676                 goto consumer_error;
1677         }
1678
1679         /*
1680          * This means that the lttng_create_session call was called with the _path_
1681          * argument set to NULL.
1682          */
1683         if (uris == NULL) {
1684                 /*
1685                  * At this point, we'll skip the consumer URI setup and create a
1686                  * session with a NULL path which will flag the session to NOT spawn a
1687                  * consumer.
1688                  */
1689                 DBG("Create session %s with NO uri, skipping consumer setup", name);
1690                 goto end;
1691         }
1692
1693         session->start_consumer = 1;
1694
1695         ret = cmd_set_consumer_uri(0, session, nb_uri, uris);
1696         if (ret != LTTCOMM_OK) {
1697                 goto consumer_error;
1698         }
1699
1700         session->consumer->enabled = 1;
1701
1702 end:
1703         return LTTCOMM_OK;
1704
1705 consumer_error:
1706         session_destroy(session);
1707 session_error:
1708 find_error:
1709         return ret;
1710 }
1711
1712 /*
1713  * Command LTTNG_DESTROY_SESSION processed by the client thread.
1714  */
1715 int cmd_destroy_session(struct ltt_session *session, int wpipe)
1716 {
1717         int ret;
1718         struct ltt_ust_session *usess;
1719         struct ltt_kernel_session *ksess;
1720
1721         /* Safety net */
1722         assert(session);
1723
1724         usess = session->ust_session;
1725         ksess = session->kernel_session;
1726
1727         /* Clean kernel session teardown */
1728         kernel_destroy_session(ksess);
1729
1730         /* UST session teardown */
1731         if (usess) {
1732                 /* Close any relayd session */
1733                 consumer_output_send_destroy_relayd(usess->consumer);
1734
1735                 /* Destroy every UST application related to this session. */
1736                 ret = ust_app_destroy_trace_all(usess);
1737                 if (ret) {
1738                         ERR("Error in ust_app_destroy_trace_all");
1739                 }
1740
1741                 /* Clean up the rest. */
1742                 trace_ust_destroy_session(usess);
1743         }
1744
1745         /*
1746          * Must notify the kernel thread here to update it's poll set in order to
1747          * remove the channel(s)' fd just destroyed.
1748          */
1749         ret = notify_thread_pipe(wpipe);
1750         if (ret < 0) {
1751                 PERROR("write kernel poll pipe");
1752         }
1753
1754         ret = session_destroy(session);
1755
1756         return ret;
1757 }
1758
1759 /*
1760  * Command LTTNG_CALIBRATE processed by the client thread.
1761  */
1762 int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
1763 {
1764         int ret;
1765
1766         switch (domain) {
1767         case LTTNG_DOMAIN_KERNEL:
1768         {
1769                 struct lttng_kernel_calibrate kcalibrate;
1770
1771                 kcalibrate.type = calibrate->type;
1772                 ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
1773                 if (ret < 0) {
1774                         ret = LTTCOMM_KERN_ENABLE_FAIL;
1775                         goto error;
1776                 }
1777                 break;
1778         }
1779         case LTTNG_DOMAIN_UST:
1780         {
1781                 struct lttng_ust_calibrate ucalibrate;
1782
1783                 ucalibrate.type = calibrate->type;
1784                 ret = ust_app_calibrate_glb(&ucalibrate);
1785                 if (ret < 0) {
1786                         ret = LTTCOMM_UST_CALIBRATE_FAIL;
1787                         goto error;
1788                 }
1789                 break;
1790         }
1791         default:
1792                 ret = LTTCOMM_UND;
1793                 goto error;
1794         }
1795
1796         ret = LTTCOMM_OK;
1797
1798 error:
1799         return ret;
1800 }
1801
1802 /*
1803  * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
1804  */
1805 int cmd_register_consumer(struct ltt_session *session, int domain,
1806                 const char *sock_path, struct consumer_data *cdata)
1807 {
1808         int ret, sock;
1809         struct consumer_socket *socket;
1810
1811         assert(session);
1812         assert(cdata);
1813         assert(sock_path);
1814
1815         switch (domain) {
1816         case LTTNG_DOMAIN_KERNEL:
1817         {
1818                 struct ltt_kernel_session *ksess = session->kernel_session;
1819
1820                 assert(ksess);
1821
1822                 /* Can't register a consumer if there is already one */
1823                 if (ksess->consumer_fds_sent != 0) {
1824                         ret = LTTCOMM_KERN_CONSUMER_FAIL;
1825                         goto error;
1826                 }
1827
1828                 sock = lttcomm_connect_unix_sock(sock_path);
1829                 if (sock < 0) {
1830                         ret = LTTCOMM_CONNECT_FAIL;
1831                         goto error;
1832                 }
1833
1834                 socket = consumer_allocate_socket(sock);
1835                 if (socket == NULL) {
1836                         ret = LTTCOMM_FATAL;
1837                         close(sock);
1838                         goto error;
1839                 }
1840
1841                 socket->lock = zmalloc(sizeof(pthread_mutex_t));
1842                 if (socket->lock == NULL) {
1843                         PERROR("zmalloc pthread mutex");
1844                         ret = LTTCOMM_FATAL;
1845                         goto error;
1846                 }
1847                 pthread_mutex_init(socket->lock, NULL);
1848                 socket->registered = 1;
1849
1850                 rcu_read_lock();
1851                 consumer_add_socket(socket, ksess->consumer);
1852                 rcu_read_unlock();
1853
1854                 pthread_mutex_lock(&cdata->pid_mutex);
1855                 cdata->pid = -1;
1856                 pthread_mutex_unlock(&cdata->pid_mutex);
1857
1858                 break;
1859         }
1860         default:
1861                 /* TODO: Userspace tracing */
1862                 ret = LTTCOMM_UND;
1863                 goto error;
1864         }
1865
1866         ret = LTTCOMM_OK;
1867
1868 error:
1869         return ret;
1870 }
1871
1872 /*
1873  * Command LTTNG_LIST_DOMAINS processed by the client thread.
1874  */
1875 ssize_t cmd_list_domains(struct ltt_session *session,
1876                 struct lttng_domain **domains)
1877 {
1878         int ret, index = 0;
1879         ssize_t nb_dom = 0;
1880
1881         if (session->kernel_session != NULL) {
1882                 DBG3("Listing domains found kernel domain");
1883                 nb_dom++;
1884         }
1885
1886         if (session->ust_session != NULL) {
1887                 DBG3("Listing domains found UST global domain");
1888                 nb_dom++;
1889         }
1890
1891         *domains = zmalloc(nb_dom * sizeof(struct lttng_domain));
1892         if (*domains == NULL) {
1893                 ret = -LTTCOMM_FATAL;
1894                 goto error;
1895         }
1896
1897         if (session->kernel_session != NULL) {
1898                 (*domains)[index].type = LTTNG_DOMAIN_KERNEL;
1899                 index++;
1900         }
1901
1902         if (session->ust_session != NULL) {
1903                 (*domains)[index].type = LTTNG_DOMAIN_UST;
1904                 index++;
1905         }
1906
1907         return nb_dom;
1908
1909 error:
1910         return ret;
1911 }
1912
1913
1914 /*
1915  * Command LTTNG_LIST_CHANNELS processed by the client thread.
1916  */
1917 ssize_t cmd_list_channels(int domain, struct ltt_session *session,
1918                 struct lttng_channel **channels)
1919 {
1920         int ret;
1921         ssize_t nb_chan = 0;
1922
1923         switch (domain) {
1924         case LTTNG_DOMAIN_KERNEL:
1925                 if (session->kernel_session != NULL) {
1926                         nb_chan = session->kernel_session->channel_count;
1927                 }
1928                 DBG3("Number of kernel channels %zd", nb_chan);
1929                 break;
1930         case LTTNG_DOMAIN_UST:
1931                 if (session->ust_session != NULL) {
1932                         nb_chan = lttng_ht_get_count(
1933                                         session->ust_session->domain_global.channels);
1934                 }
1935                 DBG3("Number of UST global channels %zd", nb_chan);
1936                 break;
1937         default:
1938                 *channels = NULL;
1939                 ret = -LTTCOMM_UND;
1940                 goto error;
1941         }
1942
1943         if (nb_chan > 0) {
1944                 *channels = zmalloc(nb_chan * sizeof(struct lttng_channel));
1945                 if (*channels == NULL) {
1946                         ret = -LTTCOMM_FATAL;
1947                         goto error;
1948                 }
1949
1950                 list_lttng_channels(domain, session, *channels);
1951         } else {
1952                 *channels = NULL;
1953         }
1954
1955         return nb_chan;
1956
1957 error:
1958         return ret;
1959 }
1960
1961 /*
1962  * Command LTTNG_LIST_EVENTS processed by the client thread.
1963  */
1964 ssize_t cmd_list_events(int domain, struct ltt_session *session,
1965                 char *channel_name, struct lttng_event **events)
1966 {
1967         int ret = 0;
1968         ssize_t nb_event = 0;
1969
1970         switch (domain) {
1971         case LTTNG_DOMAIN_KERNEL:
1972                 if (session->kernel_session != NULL) {
1973                         nb_event = list_lttng_kernel_events(channel_name,
1974                                         session->kernel_session, events);
1975                 }
1976                 break;
1977         case LTTNG_DOMAIN_UST:
1978         {
1979                 if (session->ust_session != NULL) {
1980                         nb_event = list_lttng_ust_global_events(channel_name,
1981                                         &session->ust_session->domain_global, events);
1982                 }
1983                 break;
1984         }
1985         default:
1986                 ret = -LTTCOMM_UND;
1987                 goto error;
1988         }
1989
1990         ret = nb_event;
1991
1992 error:
1993         return ret;
1994 }
1995
1996 /*
1997  * Using the session list, filled a lttng_session array to send back to the
1998  * client for session listing.
1999  *
2000  * The session list lock MUST be acquired before calling this function. Use
2001  * session_lock_list() and session_unlock_list().
2002  */
2003 void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
2004                 gid_t gid)
2005 {
2006         int ret;
2007         unsigned int i = 0;
2008         struct ltt_session *session;
2009         struct ltt_session_list *list = session_get_list();
2010
2011         DBG("Getting all available session for UID %d GID %d",
2012                         uid, gid);
2013         /*
2014          * Iterate over session list and append data after the control struct in
2015          * the buffer.
2016          */
2017         cds_list_for_each_entry(session, &list->head, list) {
2018                 /*
2019                  * Only list the sessions the user can control.
2020                  */
2021                 if (!session_access_ok(session, uid, gid)) {
2022                         continue;
2023                 }
2024
2025                 struct ltt_kernel_session *ksess = session->kernel_session;
2026                 struct ltt_ust_session *usess = session->ust_session;
2027
2028                 if (session->consumer->type == CONSUMER_DST_NET ||
2029                                 (ksess && ksess->consumer->type == CONSUMER_DST_NET) ||
2030                                 (usess && usess->consumer->type == CONSUMER_DST_NET)) {
2031                         ret = build_network_session_path(sessions[i].path,
2032                                         sizeof(session[i].path), session);
2033                 } else {
2034                         ret = snprintf(sessions[i].path, sizeof(session[i].path), "%s",
2035                                         session->consumer->dst.trace_path);
2036                 }
2037                 if (ret < 0) {
2038                         PERROR("snprintf session path");
2039                         continue;
2040                 }
2041
2042                 strncpy(sessions[i].name, session->name, NAME_MAX);
2043                 sessions[i].name[NAME_MAX - 1] = '\0';
2044                 sessions[i].enabled = session->enabled;
2045                 i++;
2046         }
2047 }
2048
2049 /*
2050  * Command LTTNG_DISABLE_CONSUMER processed by the client thread.
2051  */
2052 int cmd_disable_consumer(int domain, struct ltt_session *session)
2053 {
2054         int ret;
2055         struct ltt_kernel_session *ksess = session->kernel_session;
2056         struct ltt_ust_session *usess = session->ust_session;
2057         struct consumer_output *consumer;
2058
2059         assert(session);
2060
2061         if (session->enabled) {
2062                 /* Can't disable consumer on an already started session */
2063                 ret = LTTCOMM_TRACE_ALREADY_STARTED;
2064                 goto error;
2065         }
2066
2067         if (!session->start_consumer) {
2068                 ret = LTTCOMM_NO_CONSUMER;
2069                 goto error;
2070         }
2071
2072         switch (domain) {
2073         case 0:
2074                 DBG("Disable tracing session %s consumer", session->name);
2075                 consumer = session->consumer;
2076                 break;
2077         case LTTNG_DOMAIN_KERNEL:
2078                 /* Code flow error if we don't have a kernel session here. */
2079                 assert(ksess);
2080
2081                 DBG("Disabling kernel consumer");
2082                 consumer = ksess->consumer;
2083
2084                 break;
2085         case LTTNG_DOMAIN_UST:
2086                 /* Code flow error if we don't have a UST session here. */
2087                 assert(usess);
2088
2089                 DBG("Disabling UST consumer");
2090                 consumer = usess->consumer;
2091
2092                 break;
2093         default:
2094                 ret = LTTCOMM_UNKNOWN_DOMAIN;
2095                 goto error;
2096         }
2097
2098         if (consumer) {
2099                 consumer->enabled = 0;
2100                 /* Success at this point */
2101                 ret = LTTCOMM_OK;
2102         } else {
2103                 ret = LTTCOMM_NO_CONSUMER;
2104         }
2105
2106 error:
2107         return ret;
2108 }
2109
2110 /*
2111  * Command LTTNG_ENABLE_CONSUMER processed by the client thread.
2112  */
2113 int cmd_enable_consumer(int domain, struct ltt_session *session)
2114 {
2115         int ret;
2116         struct ltt_kernel_session *ksess = session->kernel_session;
2117         struct ltt_ust_session *usess = session->ust_session;
2118         struct consumer_output *consumer = NULL;
2119
2120         assert(session);
2121
2122         /* Can't enable consumer after session started. */
2123         if (session->enabled) {
2124                 ret = LTTCOMM_TRACE_ALREADY_STARTED;
2125                 goto error;
2126         }
2127
2128         if (!session->start_consumer) {
2129                 ret = LTTCOMM_NO_CONSUMER;
2130                 goto error;
2131         }
2132
2133         switch (domain) {
2134         case 0:
2135                 assert(session->consumer);
2136                 consumer = session->consumer;
2137                 break;
2138         case LTTNG_DOMAIN_KERNEL:
2139                 /* Code flow error if we don't have a kernel session here. */
2140                 assert(ksess);
2141
2142                 /*
2143                  * Check if we have already sent fds to the consumer. In that case,
2144                  * the enable-consumer command can't be used because a start trace
2145                  * had previously occured.
2146                  */
2147                 if (ksess->consumer_fds_sent) {
2148                         ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2149                         goto error;
2150                 }
2151
2152                 consumer = ksess->tmp_consumer;
2153                 if (consumer == NULL) {
2154                         ret = LTTCOMM_OK;
2155                         /* No temp. consumer output exists. Using the current one. */
2156                         DBG3("No temporary consumer. Using default");
2157                         consumer = ksess->consumer;
2158                         goto error;
2159                 }
2160
2161                 switch (consumer->type) {
2162                 case CONSUMER_DST_LOCAL:
2163                         DBG2("Consumer output is local. Creating directory(ies)");
2164
2165                         /* Create directory(ies) */
2166                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2167                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2168                         if (ret < 0) {
2169                                 if (ret != -EEXIST) {
2170                                         ERR("Trace directory creation error");
2171                                         ret = LTTCOMM_FATAL;
2172                                         goto error;
2173                                 }
2174                         }
2175                         break;
2176                 case CONSUMER_DST_NET:
2177                         DBG2("Consumer output is network. Validating URIs");
2178                         /* Validate if we have both control and data path set. */
2179                         if (!consumer->dst.net.control_isset) {
2180                                 ret = LTTCOMM_URL_CTRL_MISS;
2181                                 goto error;
2182                         }
2183
2184                         if (!consumer->dst.net.data_isset) {
2185                                 ret = LTTCOMM_URL_DATA_MISS;
2186                                 goto error;
2187                         }
2188
2189                         /* Check established network session state */
2190                         if (session->net_handle == 0) {
2191                                 ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2192                                 ERR("Session network handle is not set on enable-consumer");
2193                                 goto error;
2194                         }
2195
2196                         break;
2197                 }
2198
2199                 /* Append default kernel trace dir to subdir */
2200                 strncat(ksess->consumer->subdir, DEFAULT_KERNEL_TRACE_DIR,
2201                                 sizeof(ksess->consumer->subdir) -
2202                                 strlen(ksess->consumer->subdir) - 1);
2203
2204                 /*
2205                  * @session-lock
2206                  * This is race free for now since the session lock is acquired before
2207                  * ending up in this function. No other threads can access this kernel
2208                  * session without this lock hence freeing the consumer output object
2209                  * is valid.
2210                  */
2211                 rcu_read_lock();
2212                 consumer_destroy_output(ksess->consumer);
2213                 rcu_read_unlock();
2214                 ksess->consumer = consumer;
2215                 ksess->tmp_consumer = NULL;
2216
2217                 break;
2218         case LTTNG_DOMAIN_UST:
2219                 /* Code flow error if we don't have a UST session here. */
2220                 assert(usess);
2221
2222                 /*
2223                  * Check if we have already sent fds to the consumer. In that case,
2224                  * the enable-consumer command can't be used because a start trace
2225                  * had previously occured.
2226                  */
2227                 if (usess->start_trace) {
2228                         ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2229                         goto error;
2230                 }
2231
2232                 consumer = usess->tmp_consumer;
2233                 if (consumer == NULL) {
2234                         ret = LTTCOMM_OK;
2235                         /* No temp. consumer output exists. Using the current one. */
2236                         DBG3("No temporary consumer. Using default");
2237                         consumer = usess->consumer;
2238                         goto error;
2239                 }
2240
2241                 switch (consumer->type) {
2242                 case CONSUMER_DST_LOCAL:
2243                         DBG2("Consumer output is local. Creating directory(ies)");
2244
2245                         /* Create directory(ies) */
2246                         ret = run_as_mkdir_recursive(consumer->dst.trace_path,
2247                                         S_IRWXU | S_IRWXG, session->uid, session->gid);
2248                         if (ret < 0) {
2249                                 if (ret != -EEXIST) {
2250                                         ERR("Trace directory creation error");
2251                                         ret = LTTCOMM_FATAL;
2252                                         goto error;
2253                                 }
2254                         }
2255                         break;
2256                 case CONSUMER_DST_NET:
2257                         DBG2("Consumer output is network. Validating URIs");
2258                         /* Validate if we have both control and data path set. */
2259                         if (!consumer->dst.net.control_isset) {
2260                                 ret = LTTCOMM_URL_CTRL_MISS;
2261                                 goto error;
2262                         }
2263
2264                         if (!consumer->dst.net.data_isset) {
2265                                 ret = LTTCOMM_URL_DATA_MISS;
2266                                 goto error;
2267                         }
2268
2269                         /* Check established network session state */
2270                         if (session->net_handle == 0) {
2271                                 ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2272                                 DBG2("Session network handle is not set on enable-consumer");
2273                                 goto error;
2274                         }
2275
2276                         if (consumer->net_seq_index == -1) {
2277                                 ret = LTTCOMM_ENABLE_CONSUMER_FAIL;
2278                                 DBG2("Network index is not set on the consumer");
2279                                 goto error;
2280                         }
2281
2282                         break;
2283                 }
2284
2285                 /* Append default kernel trace dir to subdir */
2286                 strncat(usess->consumer->subdir, DEFAULT_UST_TRACE_DIR,
2287                                 sizeof(usess->consumer->subdir) -
2288                                 strlen(usess->consumer->subdir) - 1);
2289
2290                 /*
2291                  * @session-lock
2292                  * This is race free for now since the session lock is acquired before
2293                  * ending up in this function. No other threads can access this kernel
2294                  * session without this lock hence freeing the consumer output object
2295                  * is valid.
2296                  */
2297                 rcu_read_lock();
2298                 consumer_destroy_output(usess->consumer);
2299                 rcu_read_unlock();
2300                 usess->consumer = consumer;
2301                 usess->tmp_consumer = NULL;
2302
2303                 break;
2304         }
2305
2306         /* Enable it */
2307         if (consumer) {
2308                 consumer->enabled = 1;
2309                 /* Success at this point */
2310                 ret = LTTCOMM_OK;
2311         } else {
2312                 /* Should not really happend... */
2313                 ret = LTTCOMM_NO_CONSUMER;
2314         }
2315
2316 error:
2317         return ret;
2318 }
2319
2320 /*
2321  * Init command subsystem.
2322  */
2323 void cmd_init(void)
2324 {
2325         /*
2326          * Set network sequence index to 1 for streams to match a relayd socket on
2327          * the consumer side.
2328          */
2329         uatomic_set(&relayd_net_seq_idx, 1);
2330
2331         DBG("Command subsystem initialized");
2332 }